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Luo J, Sun A, Yu Y, Pei Y, Zuo Y, Hu Z. Periplocoside P affects synaptic transmission at the neuromuscular junction and reduces synaptic excitability in Drosophila melanogaster by inhibiting V-ATPase. PEST MANAGEMENT SCIENCE 2023; 79:5044-5052. [PMID: 37556562 DOI: 10.1002/ps.7705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/02/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Periplocoside P (PSP) is a major component of Periploca sepium Bunge known for its potent insecticidal activity. V-Type adenosine triphosphatase (V-ATPase), which is widely distributed in the cytoplasmic membranes and organelles of eukaryotic cells, plays a crucial role in synaptic excitability conduction. Previous research has shown that PSP targets the apical membrane of goblet cells in the insect midgut. However, the effects of PSP on synaptic transmission at the neuromuscular junction are often overlooked. RESULTS The bioassay revealed that Drosophila adults with different genetic backgrounds showed varying levels of susceptibility to PSP in the order: parats1 > parats1 ;DSC1-/- ≈ w1118 > DSC1-/- . Intracellular electrode recording demonstrated that PSP, similar to bafilomycin A1, had an impact on the amplitude of the excitatory junction potential (EJP) and accelerated excitability decay. Furthermore, the alteration in EJP amplitude is concentration-dependent. Another surprising discovery was that the knockout DSC1 channel showed insensitivity to PSP. CONCLUSION Our findings confirm that PSP can influence synaptic transmission at the neuromuscular junction of Drosophila larvae by targeting V-ATPase. These results provide a basis for investigating the mechanism of action of PSP and its potential application in designing novel insecticides. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jiaojiao Luo
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Anqi Sun
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Yang Yu
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Yakun Pei
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
| | - Yayun Zuo
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Northwest A&F Univeristy, Yangling, Shaanxi, China
| | - Zhaonong Hu
- Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Northwest A&F Univeristy, Yangling, Shaanxi, China
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2
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Qie X, Ren Y, Chen X, Du Y, Dong K, Hu Z. Role of DSC1 in Drosophila melanogaster synaptic activities in response to haedoxan A. INSECT SCIENCE 2023; 30:1677-1688. [PMID: 36752392 DOI: 10.1111/1744-7917.13180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/12/2023] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
Drosophila sodium channel 1 (DSC1) encodes a voltage-gated divalent cation channel that mediates neuronal excitability in insects. Previous research revealed that DSC1 knockout Drosophila melanogaster conferred different susceptibility to insecticides, which indicated the vital regulation role of DSC1 under insecticide stress. Haedoxan A (HA) is a lignan compound isolated from Phryma leptostachya, and we found that HA has excellent insecticidal activity and is worthy of further study as a botanical insecticide. Herein, we performed bioassay and electrophysiological experiments to test the biological and neural changes in the larval Drosophila with/without DSC1 knockout in response to HA. Bioassay results showed that knockout of DSC1 reduced the sensitivity to HA in both w1118 (a common wild-type strain in the laboratory) and parats1 (a pyrethroid-resistant strain) larvae. Except for parats1 /DSC1-/- , electrophysiology results implicated that HA delayed the decay rate and increased the frequency of miniature excitatory junctional potentials of Drosophila from w1118 , parats1 , and DSC1-/- strains. Moreover, the neuromuscular synapse excitatory activities of parats1 /DSC1-/- larvae were more sensitive to HA than DSC1-/- larvae, which further confirmed the functional contribution of DSC1 to neuronal excitability. Collectively, these results indicated that the DSC1 channel not only regulated the insecticidal activity of HA, but also maintained the stability of neural circuits through functional interaction with voltage-gated sodium channels. Therefore, our study provides useful information for elucidating the regulatory mechanism of DSC1 in the neural system of insects involving the action of HA derived from P. leptostachya.
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Affiliation(s)
- Xingtao Qie
- Institution of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
- Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi Province, China
- Department of Plant Protection, College of Plant Protection, Shanxi Agricultural University, Taigu, Shanxi Province, China
| | - Yaxin Ren
- Institution of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
- Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi Province, China
| | - Xueting Chen
- Institution of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
- Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi Province, China
| | - Yuzhe Du
- Southern Insect Management Research Unit, Agricultural Research Service, United States Department of Agriculture, Stoneville, MS, USA
| | - Ke Dong
- Department of Biology, Duke University, Durham, NC, USA
| | - Zhaonong Hu
- Institution of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province, China
- Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi Province, China
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, Shanxi Province, China
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3
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Shaheen A, Richter Gorey CL, Sghaier A, Dason JS. Cholesterol is required for activity-dependent synaptic growth. J Cell Sci 2023; 136:jcs261563. [PMID: 37902091 DOI: 10.1242/jcs.261563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/24/2023] [Indexed: 10/31/2023] Open
Abstract
Changes in cholesterol content of neuronal membranes occur during development and brain aging. Little is known about whether synaptic activity regulates cholesterol levels in neuronal membranes and whether these changes affect neuronal development and function. We generated transgenic flies that express the cholesterol-binding D4H domain of perfringolysin O toxin and found increased levels of cholesterol in presynaptic terminals of Drosophila larval neuromuscular junctions following increased synaptic activity. Reduced cholesterol impaired synaptic growth and largely prevented activity-dependent synaptic growth. Presynaptic knockdown of adenylyl cyclase phenocopied the impaired synaptic growth caused by reducing cholesterol. Furthermore, the effects of knocking down adenylyl cyclase and reducing cholesterol were not additive, suggesting that they function in the same pathway. Increasing cAMP levels using a dunce mutant with reduced phosphodiesterase activity failed to rescue this impaired synaptic growth, suggesting that cholesterol functions downstream of cAMP. We used a protein kinase A (PKA) sensor to show that reducing cholesterol levels reduced presynaptic PKA activity. Collectively, our results demonstrate that enhanced synaptic activity increased cholesterol levels in presynaptic terminals and that these changes likely activate the cAMP-PKA pathway during activity-dependent growth.
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Affiliation(s)
- Amber Shaheen
- Department of Biomedical Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
| | - Claire L Richter Gorey
- Department of Biomedical Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
| | - Adam Sghaier
- Department of Biomedical Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
| | - Jeffrey S Dason
- Department of Biomedical Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
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4
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Dason JS, Sokolowski MB. A cGMP-dependent protein kinase, encoded by the Drosophila foraging gene, regulates neurotransmission through changes in synaptic structure and function. J Neurogenet 2021; 35:213-220. [PMID: 33998378 DOI: 10.1080/01677063.2021.1905639] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A cGMP-dependent protein kinase (PKG) encoded by the Drosophila foraging (for) gene regulates both synaptic structure (nerve terminal growth) and function (neurotransmission) through independent mechanisms at the Drosophila larval neuromuscular junction (nmj). Glial for is known to restrict nerve terminal growth, whereas presynaptic for inhibits synaptic vesicle (SV) exocytosis during low frequency stimulation. Presynaptic for also facilitates SV endocytosis during high frequency stimulation. for's effects on neurotransmission can occur independent of any changes in nerve terminal growth. However, it remains unclear if for's effects on neurotransmission affect nerve terminal growth. Furthermore, it's possible that for's effects on synaptic structure contribute to changes in neurotransmission. In the present study, we examined these questions using RNA interference to selectively knockdown for in presynaptic neurons or glia at the Drosophila larval nmj. Consistent with our previous findings, presynaptic knockdown of for impaired SV endocytosis, whereas knockdown of glial for had no effect on SV endocytosis. Surprisingly, we found that knockdown of either presynaptic or glial for increased neurotransmitter release in response to low frequency stimulation. Knockdown of presynaptic for did not affect nerve terminal growth, demonstrating that for's effects on neurotransmission does not alter nerve terminal growth. In contrast, knockdown of glial for enhanced nerve terminal growth. This enhanced nerve terminal growth was likely the cause of the enhanced neurotransmitter release seen following knockdown of glial for. Overall, we show that for can affect neurotransmitter release by regulating both synaptic structure and function.
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Affiliation(s)
- Jeffrey S Dason
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Biomedical Sciences, University of Windsor, Windsor, Canada
| | - Marla B Sokolowski
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
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5
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Al Kassaa I, Mechmchani S, Zaylaa M, Bachar Ismail M, El Omari K, Dabboussi F, Hamze M. Enterococcus faecium CMUL1216 an Immunobiotic Strain with a Potential Application in Animal Sector. Biocontrol Sci 2021; 26:75-84. [PMID: 34092717 DOI: 10.4265/bio.26.75] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Antibiotic misuse in the animal sector is the first cause of the emergence and spreading of MDR bacteria. Prevention of infectious diseases and enhancement of animal growth are the main effects of antibiotics that push farmers and veterinarians to use this molecule in animal farms. Thus, the use of alternative solutions such as natural antimicrobial substances as well as probiotic strains is a crucial need in this sector. Enterococcus faecium CMUL1216 was isolated from healthy human baby's feces. This strain was assessed in vitro for probiotic properties including activity against many pathogens isolated from animal, human, and soil samples. CMUL1216 strain exhibits good antimicrobial activity against indicator pathogens in both planktonic and biofilm forms. In addition, CMUL1216 strain showed a strong biofilm formation. Furthermore, CMUL1216 exhibits a good anti-inflammatory effect by inducing the secretion of IL-10 in vitro. Moreover, this strain did not show any pathogenic characteristics such as hemolytic effect, presence of virulence genes as well as susceptibility to the majority of antibiotic families. E. faecium CMUL1216 could be a good candidate to be used a probiotic strain in the animal sector in order to maintain animal health and therefore reduce antibiotic resistance caused by the excessive use in this sector.
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Affiliation(s)
- Imad Al Kassaa
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University.,Faculty of Public Health, Lebanese University
| | - Samah Mechmchani
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University
| | - Mazen Zaylaa
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University
| | - Mohamad Bachar Ismail
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University
| | - Khaled El Omari
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University.,Faculty of Public Health, Lebanese University.,Quality Control Center Laboratories at the Chamber of Commerce, Industry Agriculture of Tripoli and North Lebanon
| | - Fouad Dabboussi
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University.,Faculty of Public Health, Lebanese University
| | - Monzer Hamze
- Laboratoire de Microbiologie Santé et Environnement (LMSE), Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University.,Faculty of Public Health, Lebanese University
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6
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Lnenicka GA. Crayfish and Drosophila NMJs. Neurosci Lett 2020; 732:135110. [PMID: 32497734 DOI: 10.1016/j.neulet.2020.135110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 01/06/2023]
Abstract
Many synaptic studies have utilized the experimental advantages of the Arthropod NMJ and the most prominent preparations have been the crayfish and Drosophila larval NMJs. Early cellular studies in the crayfish established the framework for later molecular studies in Drosophila. The two neuromuscular systems are compared including the advantages presented by each preparation for cellular analysis. Beginning with the early work in the crayfish, research developments are followed in the areas of structure/function relationships, activity-dependent synaptic plasticity/development and synaptic homeostasis. A reoccurring theme in these studies is the regulation of active zone structure and function. Early studies in the crayfish focused on the role of active zone number/size and possible functional heterogeneity in regulating transmitter release. Recent studies in Drosophila have begun to characterize this heterogeneity using new approaches that combine imaging of transmitter release, Ca2+ influx and molecular composition for individual active zones.
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Affiliation(s)
- Gregory A Lnenicka
- Department of Biological Sciences, University at Albany, SUNY, Albany, NY 12222, United States.
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7
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Odierna GL, Kerwin SK, Harris LE, Shin GJE, Lavidis NA, Noakes PG, Millard SS. Dscam2 suppresses synaptic strength through a PI3K-dependent endosomal pathway. J Cell Biol 2020; 219:151621. [PMID: 32259198 PMCID: PMC7265308 DOI: 10.1083/jcb.201909143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/19/2020] [Accepted: 03/05/2020] [Indexed: 11/22/2022] Open
Abstract
Dscam2 is a cell surface protein required for neuronal development in Drosophila; it can promote neural wiring through homophilic recognition that leads to either adhesion or repulsion between neurites. Here, we report that Dscam2 also plays a post-developmental role in suppressing synaptic strength. This function is dependent on one of two distinct extracellular isoforms of the protein and is autonomous to motor neurons. We link the PI3K enhancer, Centaurin gamma 1A, to the Dscam2-dependent regulation of synaptic strength and show that changes in phosphoinositide levels correlate with changes in endosomal compartments that have previously been associated with synaptic strength. Using transmission electron microscopy, we find an increase in synaptic vesicles at Dscam2 mutant active zones, providing a rationale for the increase in synaptic strength. Our study provides the first evidence that Dscam2 can regulate synaptic physiology and highlights how diverse roles of alternative protein isoforms can contribute to unique aspects of brain development and function.
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Affiliation(s)
- G Lorenzo Odierna
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Sarah K Kerwin
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Lucy E Harris
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Grace Ji-Eun Shin
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - S Sean Millard
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
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8
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Guo H, Li Y, Shen L, Wang T, Jia X, Liu L, Xu T, Ou M, Hoekzema K, Wu H, Gillentine MA, Liu C, Ni H, Peng P, Zhao R, Zhang Y, Phornphutkul C, Stegmann APA, Prada CE, Hopkin RJ, Shieh JT, McWalter K, Monaghan KG, van Hasselt PM, van Gassen K, Bai T, Long M, Han L, Quan Y, Chen M, Zhang Y, Li K, Zhang Q, Tan J, Zhu T, Liu Y, Pang N, Peng J, Scott DA, Lalani SR, Azamian M, Mancini GMS, Adams DJ, Kvarnung M, Lindstrand A, Nordgren A, Pevsner J, Osei-Owusu IA, Romano C, Calabrese G, Galesi O, Gecz J, Haan E, Ranells J, Racobaldo M, Nordenskjold M, Madan-Khetarpal S, Sebastian J, Ball S, Zou X, Zhao J, Hu Z, Xia F, Liu P, Rosenfeld JA, de Vries BBA, Bernier RA, Xu ZQD, Li H, Xie W, Hufnagel RB, Eichler EE, Xia K. Disruptive variants of CSDE1 associate with autism and interfere with neuronal development and synaptic transmission. SCIENCE ADVANCES 2019; 5:eaax2166. [PMID: 31579823 PMCID: PMC6760934 DOI: 10.1126/sciadv.aax2166] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/27/2019] [Indexed: 05/30/2023]
Abstract
RNA binding proteins are key players in posttranscriptional regulation and have been implicated in neurodevelopmental and neuropsychiatric disorders. Here, we report a significant burden of heterozygous, likely gene-disrupting variants in CSDE1 (encoding a highly constrained RNA binding protein) among patients with autism and related neurodevelopmental disabilities. Analysis of 17 patients identifies common phenotypes including autism, intellectual disability, language and motor delay, seizures, macrocephaly, and variable ocular abnormalities. HITS-CLIP revealed that Csde1-binding targets are enriched in autism-associated gene sets, especially FMRP targets, and in neuronal development and synaptic plasticity-related pathways. Csde1 knockdown in primary mouse cortical neurons leads to an overgrowth of the neurites and abnormal dendritic spine morphology/synapse formation and impaired synaptic transmission, whereas mutant and knockdown experiments in Drosophila result in defects in synapse growth and synaptic transmission. Our study defines a new autism-related syndrome and highlights the functional role of CSDE1 in synapse development and synaptic transmission.
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Affiliation(s)
- Hui Guo
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Ying Li
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Lu Shen
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Tianyun Wang
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Xiangbin Jia
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Lijuan Liu
- Institute of Life Sciences, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
| | - Tao Xu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Mengzhu Ou
- Institute of Life Sciences, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
| | - Kendra Hoekzema
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Huidan Wu
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Madelyn A. Gillentine
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Cenying Liu
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Hailun Ni
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Pengwei Peng
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Rongjuan Zhao
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yu Zhang
- Key Laboratory of Developmental Disorders in Children, Liuzhou Maternity and Child Healthcare Hospital, Liuzhou, Guangxi, China
| | - Chanika Phornphutkul
- Division of Human Genetics, Warren Alpert Medical School of Brown University, Hasbro Children's Hospital/Rhode Island Hospital, Providence, RI, USA
| | | | - Carlos E. Prada
- Department of Pediatrics, University of Cincinnati College of Medicine, Division of Human Genetics, Cincinnati Children’s Hospital, Cincinnati, OH, USA
| | - Robert J. Hopkin
- Department of Pediatrics, University of Cincinnati College of Medicine, Division of Human Genetics, Cincinnati Children’s Hospital, Cincinnati, OH, USA
| | - Joseph T. Shieh
- Institute for Human Genetics and Department of Pediatrics, University of California, San Francisco, San Francisco, CA, USA
| | | | | | | | | | - Ting Bai
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Min Long
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Lin Han
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yingting Quan
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Meilin Chen
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yaowen Zhang
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Kuokuo Li
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Qiumeng Zhang
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Jieqiong Tan
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Tengfei Zhu
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yaning Liu
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Daryl A. Scott
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Seema R. Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Mahshid Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Grazia M. S. Mancini
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Darius J. Adams
- Goryeb Children’s Hospital, Atlantic Health System, Morristown, NJ, USA
| | - Malin Kvarnung
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Ann Nordgren
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Jonathan Pevsner
- Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, USA
- Program in Human Genetics, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ikeoluwa A. Osei-Owusu
- Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, USA
- Program in Human Genetics, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | | | | | - Jozef Gecz
- School of Medicine and the Robinson Research Institute, University of Adelaide at the Women’s and Children’s Hospital, Adelaide, South Australia, Australia
| | - Eric Haan
- Adult Genetics Unit, Royal Adelaide Hospital, and School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - Judith Ranells
- Department of Pediatrics, University of South Florida, Tampa, FL, USA
| | - Melissa Racobaldo
- Department of Pediatrics, University of South Florida, Tampa, FL, USA
| | - Magnus Nordenskjold
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Suneeta Madan-Khetarpal
- Division of Medical Genetics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | - Jessica Sebastian
- Division of Medical Genetics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | - Susie Ball
- Central Washington Genetics Program, Virginia Mason Memorial, Yakima, WA, USA
| | - Xiaobing Zou
- Children Development Behavior Center of the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jingping Zhao
- Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhengmao Hu
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Fan Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Baylor Genetics, Houston, TX, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Baylor Genetics, Houston, TX, USA
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Bert B. A. de Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Zhi-Qing David Xu
- Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Laboratory of Brain Disorders (Ministry of Science and Technology), Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Honghui Li
- Key Laboratory of Developmental Disorders in Children, Liuzhou Maternity and Child Healthcare Hospital, Liuzhou, Guangxi, China
| | - Wei Xie
- Institute of Life Sciences, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
| | - Robert B. Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, NIH, Bethesda, MD, USA
| | - Evan E. Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
| | - Kun Xia
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
- Key Laboratory of Medical Information Research, Central South University, Changsha, Hunan, China
- CAS Center for Excellence in Brain Science and Intelligences Technology (CEBSIT), Chinese Academy of Sciences, Shanghai 200030, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan 410078, China
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9
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Lecompte M, Cattaert D, Vincent A, Birman S, Chérif-Zahar B. Drosophila ammonium transporter Rh50 is required for integrity of larval muscles and neuromuscular system. J Comp Neurol 2019; 528:81-94. [PMID: 31273786 DOI: 10.1002/cne.24742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 05/30/2019] [Accepted: 06/21/2019] [Indexed: 12/18/2022]
Abstract
Rhesus glycoproteins (Rh50) have been shown to be ammonia transporters in many species from bacteria to human. They are involved in various physiological processes including acid excretion and pH regulation. Rh50 proteins can also provide a structural link between the cytoskeleton and the plasma membranes that maintain cellular integrity. Although ammonia plays essential roles in the nervous system, in particular at glutamatergic synapses, a potential role for Rh50 proteins at synapses has not yet been investigated. To better understand the function of these proteins in vivo, we studied the unique Rh50 gene of Drosophila melanogaster, which encodes two isoforms, Rh50A and Rh50BC. We found that Drosophila Rh50A is expressed in larval muscles and enriched in the postsynaptic regions of the glutamatergic neuromuscular junctions. Rh50 inactivation by RNA interference selectively in muscle cells caused muscular atrophy in larval stages and pupal lethality. Interestingly, Rh50-deficiency in muscles specifically increased glutamate receptor subunit IIA (GluRIIA) level and the frequency of spontaneous excitatory postsynaptic potentials. Our work therefore highlights a new role for Rh50 proteins in the maintenance of Drosophila muscle architecture and synaptic physiology, which could be conserved in other species.
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Affiliation(s)
- Mathilde Lecompte
- Genes Circuits Rhythmes et Neuropathologies, Plasticité du Cerveau, ESPCI Paris, CNRS, PSL University, Paris, France
| | - Daniel Cattaert
- Institut des Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, Bordeaux University, Bordeaux, France
| | - Alain Vincent
- Centre de Biologie du Développement, Centre de Biologie Intégrative, CNRS, Toulouse University, UPS, Toulouse, France
| | - Serge Birman
- Genes Circuits Rhythmes et Neuropathologies, Plasticité du Cerveau, ESPCI Paris, CNRS, PSL University, Paris, France
| | - Baya Chérif-Zahar
- Genes Circuits Rhythmes et Neuropathologies, Plasticité du Cerveau, ESPCI Paris, CNRS, PSL University, Paris, France
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10
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Bollinger WL, St. Germain EJ, Maki SL, Sial NK, Lepore SD, Dawson-Scully K. Resveratrol-Inspired Bridged Bicyclic Compounds: A New Compound Class for the Protection of Synaptic Function from Acute Oxidative Stress. ACS Chem Neurosci 2019; 10:221-225. [PMID: 30462482 DOI: 10.1021/acschemneuro.8b00577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
While resveratrol protects organisms from the deleterious effects of oxidative stress, its multifarious mechanism of action limits its potential as a selective medicinal agent. To address this shortcoming, we have designed a molecular scaffold that we have termed a resveramorph. The structure of this compound class possesses much of the functional group characteristics of resveratrol but in a nonplanar molecular arrangement, and, in the present work, we probe the neuroprotective activities of two resveramorph analogues. These novel compounds were found to protect neurotransmission from hydrogen peroxide-induced oxidative stress. Our findings demonstrate that, at a subnanomolar level, one analogue, resveramorph 1, protects synaptic transmission from acute oxidative stress at the Drosophila neuromuscular junction. These results position resveramorphs as potential lead compounds in the development of new drugs for neurodegenerative diseases.
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Affiliation(s)
- Wesley L. Bollinger
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Elijah J. St. Germain
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Samantha L. Maki
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Nadia K. Sial
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida 33431, United States
- Brain Institute, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Salvatore D. Lepore
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida 33431, United States
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11
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Dason JS, Allen AM, Vasquez OE, Sokolowski MB. Distinct functions of a cGMP-dependent protein kinase in nerve terminal growth and synaptic vesicle cycling. J Cell Sci 2019; 132:jcs.227165. [DOI: 10.1242/jcs.227165] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/26/2019] [Indexed: 01/20/2023] Open
Abstract
Sustained neurotransmission requires the tight coupling of synaptic vesicle (SV) exocytosis and endocytosis. The mechanisms underlying this coupling are poorly understood. We tested the hypothesis that a cGMP-dependent protein kinase (PKG), encoded by the foraging (for) gene in Drosophila melanogaster, is critical for this process using a for null mutant, genomic rescues, and tissue specific rescues. We uncoupled FOR's exocytic and endocytic functions in neurotransmission using a temperature-sensitive shibire mutant in conjunction with fluorescein-assisted light inactivation of FOR. We discovered a dual role for presynaptic FOR, where FOR inhibits SV exocytosis during low frequency stimulation by negatively regulating presynaptic Ca2+ levels and maintains neurotransmission during high frequency stimulation by facilitating SV endocytosis. Additionally, glial FOR negatively regulated nerve terminal growth through TGF-β signaling and this developmental effect was independent from FOR's effects on neurotransmission. Overall, FOR plays a critical role in coupling SV exocytosis and endocytosis, thereby balancing these two components to maintain sustained neurotransmission.
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Affiliation(s)
- Jeffrey S. Dason
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Department of Biological Sciences, University of Windsor, Windsor, Ontario, N9B 3P4, Canada
| | - Aaron M. Allen
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Present Address: Centre for Neural Circuits and Behaviour, University of Oxford, OX1 3SR Oxford, UK
| | - Oscar E. Vasquez
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
| | - Marla B. Sokolowski
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3B2, Canada
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, M5G 1M1, Canada
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12
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Ou M, Wang S, Sun M, An J, Lv H, Zeng X, Hou SX, Xie W. The PDZ-GEF Gef26 regulates synapse development and function via FasII and Rap1 at the Drosophila neuromuscular junction. Exp Cell Res 2018; 374:342-352. [PMID: 30553967 DOI: 10.1016/j.yexcr.2018.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/09/2018] [Accepted: 12/12/2018] [Indexed: 12/29/2022]
Abstract
Guanine nucleotide exchange factors (GEFs) are essential for small G proteins to activate their downstream signaling pathways, which are involved in morphogenesis, cell adhesion, and migration. Mutants of Gef26, a PDZ-GEF (PDZ domain-containing guanine nucleotide exchange factor) in Drosophila, exhibit strong defects in wings, eyes, and the reproductive and nervous systems. However, the precise roles of Gef26 in development remain unclear. In the present study, we analyzed the role of Gef26 in synaptic development and function. We identified significant decreases in bouton number and branch length at larval neuromuscular junctions (NMJs) in Gef26 mutants, and these defects were fully rescued by restoring Gef26 expression, indicating that Gef26 plays an important role in NMJ morphogenesis. In addition to the observed defects in NMJ morphology, electrophysiological analyses revealed functional defects at NMJs, and locomotor deficiency appeared in Gef26 mutant larvae. Furthermore, Gef26 regulated NMJ morphogenesis by regulating the level of synaptic Fasciclin II (FasII), a well-studied cell adhesion molecule that functions in NMJ development and remodeling. Finally, our data demonstrate that Gef26-specific small G protein Rap1 worked downstream of Gef26 to regulate the level of FasII at NMJs, possibly through a βPS integrin-mediated signaling pathway. Taken together, our findings define a novel role of Gef26 in regulating NMJ development and function.
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Affiliation(s)
- Mengzhu Ou
- The Key Laboratory of Development Genes and Human Diseases, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Su Wang
- The Key Laboratory of Development Genes and Human Diseases, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Mingkuan Sun
- The Key Laboratory of Development Genes and Human Diseases, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Jinsong An
- The Key Laboratory of Development Genes and Human Diseases, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Huihui Lv
- The Key Laboratory of Development Genes and Human Diseases, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China
| | - Xiankun Zeng
- Basic Research Laboratory, National Cancer Institute at Frederick, NIH, Frederick, MD 21702, USA
| | - Steven X Hou
- Basic Research Laboratory, National Cancer Institute at Frederick, NIH, Frederick, MD 21702, USA.
| | - Wei Xie
- The Key Laboratory of Development Genes and Human Diseases, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China.
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13
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Dason JS, Sokolowski MB, Wu CF. A reductionist approach to understanding the nervous system: the Harold Atwood legacy. J Neurogenet 2018; 32:127-130. [PMID: 30484389 DOI: 10.1080/01677063.2018.1504044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Jeffrey S Dason
- a Department of Biological Sciences , University of Windsor , Windsor , Canada
| | - Marla B Sokolowski
- b Department of Cell & Systems Biology , University of Toronto , Toronto , Canada.,c Department of Ecology & Evolutionary Biology , University of Toronto , Toronto , Canada.,d Child and Brain Development Program , Canadian Institute for Advanced Research (CIFAR) , Toronto , Canada
| | - Chun-Fang Wu
- e Department of Biology , University of Iowa , Iowa City , IA , USA
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14
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Bollinger WL, Sial N, Dawson-Scully K. BK channels and a cGMP-dependent protein kinase (PKG) function through independent mechanisms to regulate the tolerance of synaptic transmission to acute oxidative stress at the Drosophila larval neuromuscular junction. J Neurogenet 2018; 32:246-255. [DOI: 10.1080/01677063.2018.1500571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Wesley L. Bollinger
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, USA
| | - Nadia Sial
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, USA
- Brain Institute Research Scholars Program, Florida Atlantic University, Boca Raton, FL, USA
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL, USA
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15
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He T, Nitabach MN, Lnenicka GA. Parvalbumin expression affects synaptic development and physiology at the Drosophila larval NMJ. J Neurogenet 2018; 32:209-220. [PMID: 30175644 DOI: 10.1080/01677063.2018.1498496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Presynaptic Ca2+ appears to play multiple roles in synaptic development and physiology. We examined the effect of buffering presynaptic Ca2+ by expressing parvalbumin (PV) in Drosophila neurons, which do not normally express PV. The studies were performed on the identified Ib terminal that innervates muscle fiber 5. The volume-averaged, residual Ca2+ resulting from single action potentials (APs) and AP trains was measured using the fluorescent Ca2+ indicator, OGB-1. PV reduced the amplitude and decay time constant (τ) for single-AP Ca2+ transients. For AP trains, there was a reduction in the rate of rise and decay of [Ca2+]i but the plateau [Ca2+]i was not affected. Electrophysiological recordings from muscle fiber 5 showed a reduction in paired-pulse facilitation, particularly the F1 component; this was likely due to the reduction in residual Ca2+. These synapses also showed reduced synaptic enhancement during AP trains, presumably due to less buildup of synaptic facilitation. The transmitter release for single APs was increased for the PV-expressing terminals and this may have been a homeostatic response to the decrease in facilitation. Confocal microscopy was used to examine the structure of the motor terminals and PV expression resulted in smaller motor terminals with fewer synaptic boutons and active zones. This result supports earlier proposals that increased AP activity promotes motor terminal growth through increases in presynaptic [Ca2+]i.
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Affiliation(s)
- Tao He
- a Division of Pulmonary and Critical Care Medicine , David Geffen School of Medicine at UCLA , Los Angeles , CA , USA
| | - Michael N Nitabach
- b Department of Cellular and Molecular Physiology , Yale School of Medicine , New Haven , CT , USA
| | - Gregory A Lnenicka
- c Department of Biological Sciences , University at Albany , Albany , NY , USA
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16
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Cantarutti KC, Burgess J, Brill JA, Dason JS. Type II phosphatidylinositol 4-kinase regulates nerve terminal growth and synaptic vesicle recycling. J Neurogenet 2018; 32:230-235. [DOI: 10.1080/01677063.2018.1502762] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
| | - Jason Burgess
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Julie A. Brill
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Jeffrey S. Dason
- Department of Biological Sciences, University of Windsor, Windsor, Canada
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17
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Chen X, Wang Y, Wu W, Dong K, Hu Z. DSC1 channel-dependent developmental regulation of pyrethroid susceptibility in Drosophila melanogaster. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 148:190-198. [PMID: 29891372 DOI: 10.1016/j.pestbp.2018.04.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/10/2018] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Pyrethroid insecticides modify the gating of voltage-gated sodium channels, thus disrupting the function of the nervous system. In Drosophila melanogaster, para encodes a functional sodium channel. Drosophila Sodium Channel 1 (DSC1), although considered as a putative sodium channel gene for decades due to its high sequence similarity with sodium channels, encodes a voltage-gated cation channel with high permeability to Ca2+. Previous study showed that knockout of the DSC1 gene (DSC1-/-) caused Drosophila adults to be more susceptible to pyrethroids and the adult giant fiber (GF) neural circuit were more susceptible to pyrethroids. Considering distinct expression of DSC1 transcripts in adults and larvae, we examined the role of DSC1 channels in regulating pyrethroid susceptibility in Drosophila larvae. We conducted insecticide bioassays and examined the susceptibility of the larval neuromuscular junction (NMJ) to pyrethroids using w1118, an insecticide-susceptible line, DSC1-/-, parats1 (a pyrethroid-resistant line carrying a mutation in para) and a double mutation line parats1; DSC1-/-. We found that, like the adult GF system, the NMJ of DSC1-/- flies is more susceptible to pyrethroids than that of w1118 with the pyrethroid susceptibility ranked as DSC1-/- > w1118 > parats1; DSC1-/- > parats1. However, DSC1-/- larvae were about two-fold more resistant to pyrethroids than w1118 larvae, and the pyrethroid susceptibility of larvae ranked as w1118 > DSC1-/- > parats1; DSC1-/- > parats1. These results reveal common and distinct roles of DSC1 channels in regulating the action of pyrethroids in adults and larvae of D. melanogaster.
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Affiliation(s)
- Xueting Chen
- Provincial Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Yangling, Shaanxi 712100, PR China; Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Yuanyuan Wang
- Key Laboratory of Crop Pest Integrated Management on the Loess Plateau, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China
| | - Wenjun Wu
- Provincial Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Yangling, Shaanxi 712100, PR China; Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Ke Dong
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Zhaonong Hu
- Provincial Key Laboratory for Botanical Pesticide R&D of Shaanxi Province, Yangling, Shaanxi 712100, PR China; Institute of Pesticide Science, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, PR China; Key Laboratory of Crop Pest Integrated Management on the Loess Plateau, Ministry of Agriculture, Yangling, Shaanxi 712100, PR China.
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18
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Caplan SL, Zheng B, Dawson-Scully K, White CA, West LM. Pseudopterosin A: Protection of Synaptic Function and Potential as a Neuromodulatory Agent. Mar Drugs 2016; 14:md14030055. [PMID: 26978375 PMCID: PMC4820309 DOI: 10.3390/md14030055] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 02/28/2016] [Accepted: 03/04/2016] [Indexed: 01/07/2023] Open
Abstract
Natural products have provided an invaluable source of inspiration in the drug discovery pipeline. The oceans are a vast source of biological and chemical diversity. Recently, this untapped resource has been gaining attention in the search for novel structures and development of new classes of therapeutic agents. Pseudopterosins are group of marine diterpene glycosides that possess an array of potent biological activities in several therapeutic areas. Few studies have examined pseudopterosin effects during cellular stress and, to our knowledge, no studies have explored their ability to protect synaptic function. The present study probes pseudopterosin A (PsA) for its neuromodulatory properties during oxidative stress using the fruit fly, Drosophila melanogaster. We demonstrate that oxidative stress rapidly reduces neuronal activity, resulting in the loss of neurotransmission at a well-characterized invertebrate synapse. PsA mitigates this effect and promotes functional tolerance during oxidative stress by prolonging synaptic transmission in a mechanism that differs from scavenging activity. Furthermore, the distribution of PsA within mammalian biological tissues following single intravenous injection was investigated using a validated bioanalytical method. Comparable exposure of PsA in the mouse brain and plasma indicated good distribution of PsA in the brain, suggesting its potential as a novel neuromodulatory agent.
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Affiliation(s)
- Stacee Lee Caplan
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA.
| | - Bo Zheng
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens, GA 30602, USA.
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA.
| | - Catherine A White
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens, GA 30602, USA.
| | - Lyndon M West
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens, GA 30602, USA.
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA.
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19
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Insight into the Mode of Action of Haedoxan A from Phryma leptostachya. Toxins (Basel) 2016; 8:53. [PMID: 26907348 PMCID: PMC4773806 DOI: 10.3390/toxins8020053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 02/14/2016] [Accepted: 02/15/2016] [Indexed: 11/26/2022] Open
Abstract
Haedoxan A (HA) is a major active ingredient in the herbaceous perennial plant lopseed (Phryma leptostachya L.), which is used as a natural insecticide against insect pests in East Asia. Here, we report that HA delayed the decay rate of evoked excitatory junctional potentials (EJPs) and increased the frequency of miniature EJPs (mEJPs) on the Drosophila neuromuscular junction. HA also caused a significant hyperpolarizing shift of the voltage dependence of fast inactivation of insect sodium channels expressed in Xenopus oocytes. Our results suggest that HA acts on both axonal conduction and synaptic transmission, which can serve as a basis for elucidating the mode of action of HA for further designing and developing new effective insecticides.
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20
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Slater CR. The functional organization of motor nerve terminals. Prog Neurobiol 2015; 134:55-103. [DOI: 10.1016/j.pneurobio.2015.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 08/28/2015] [Accepted: 09/05/2015] [Indexed: 12/19/2022]
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21
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Harris KP, Littleton JT. Transmission, Development, and Plasticity of Synapses. Genetics 2015; 201:345-75. [PMID: 26447126 PMCID: PMC4596655 DOI: 10.1534/genetics.115.176529] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/28/2015] [Indexed: 01/03/2023] Open
Abstract
Chemical synapses are sites of contact and information transfer between a neuron and its partner cell. Each synapse is a specialized junction, where the presynaptic cell assembles machinery for the release of neurotransmitter, and the postsynaptic cell assembles components to receive and integrate this signal. Synapses also exhibit plasticity, during which synaptic function and/or structure are modified in response to activity. With a robust panel of genetic, imaging, and electrophysiology approaches, and strong evolutionary conservation of molecular components, Drosophila has emerged as an essential model system for investigating the mechanisms underlying synaptic assembly, function, and plasticity. We will discuss techniques for studying synapses in Drosophila, with a focus on the larval neuromuscular junction (NMJ), a well-established model glutamatergic synapse. Vesicle fusion, which underlies synaptic release of neurotransmitters, has been well characterized at this synapse. In addition, studies of synaptic assembly and organization of active zones and postsynaptic densities have revealed pathways that coordinate those events across the synaptic cleft. We will also review modes of synaptic growth and plasticity at the fly NMJ, and discuss how pre- and postsynaptic cells communicate to regulate plasticity in response to activity.
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Affiliation(s)
- Kathryn P Harris
- Department of Biology and Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - J Troy Littleton
- Department of Biology and Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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22
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Karunanithi S, Brown IR. Heat shock response and homeostatic plasticity. Front Cell Neurosci 2015; 9:68. [PMID: 25814928 PMCID: PMC4357293 DOI: 10.3389/fncel.2015.00068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 02/17/2015] [Indexed: 11/13/2022] Open
Abstract
Heat shock response and homeostatic plasticity are mechanisms that afford functional stability to cells in the face of stress. Each mechanism has been investigated independently, but the link between the two has not been extensively explored. We explore this link. The heat shock response enables cells to adapt to stresses such as high temperature, metabolic stress and reduced oxygen levels. This mechanism results from the production of heat shock proteins (HSPs) which maintain normal cellular functions by counteracting the misfolding of cellular proteins. Homeostatic plasticity enables neurons and their target cells to maintain their activity levels around their respective set points in the face of stress or disturbances. This mechanism results from the recruitment of adaptations at synaptic inputs, or at voltage-gated ion channels. In this perspective, we argue that heat shock triggers homeostatic plasticity through the production of HSPs. We also suggest that homeostatic plasticity is a form of neuroprotection.
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Affiliation(s)
- Shanker Karunanithi
- School of Medical Science, Griffith University QLD, Australia ; Menzies Health Institute of Queensland, Griffith University QLD, Australia
| | - Ian R Brown
- Department of Biological Sciences, Centre for the Neurobiology of Stress, University of Toronto Scarborough Toronto, ON, Canada
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23
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Ueda A, Wu CF. The role of cAMP in synaptic homeostasis in response to environmental temperature challenges and hyperexcitability mutations. Front Cell Neurosci 2015; 9:10. [PMID: 25698925 PMCID: PMC4313691 DOI: 10.3389/fncel.2015.00010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/08/2015] [Indexed: 11/13/2022] Open
Abstract
Homeostasis is the ability of physiological systems to regain functional balance following environment or experimental insults and synaptic homeostasis has been demonstrated in various species following genetic or pharmacological disruptions. Among environmental challenges, homeostatic responses to temperature extremes are critical to animal survival under natural conditions. We previously reported that axon terminal arborization in Drosophila larval neuromuscular junctions (NMJs) is enhanced at elevated temperatures; however, the amplitude of excitatory junctional potentials (EJPs) remains unaltered despite the increase in synaptic bouton numbers. Here we determine the cellular basis of this homeostatic adjustment in larvae reared at high temperature (HT, 29°C). We found that synaptic current focally recorded from individual synaptic boutons was unaffected by rearing temperature (<15°C to >30°C). However, HT rearing decreased the quantal size (amplitude of spontaneous miniature EJPs, or mEJPs), which compensates for the increased number of synaptic releasing sites to retain a normal EJP size. The quantal size decrease is accounted for by a decrease in input resistance of the postsynaptic muscle fiber, indicating an increase in membrane area that matches the synaptic growth at HT. Interestingly, a mutation in rutabaga (rut) encoding adenylyl cyclase (AC) exhibited no obvious changes in quantal size or input resistance of postsynaptic muscle cells after HT rearing, suggesting an important role for rut AC in temperature-induced synaptic homeostasis in Drosophila. This extends our previous finding of rut-dependent synaptic homeostasis in hyperexcitable mutants, e.g., slowpoke (slo). In slo larvae, the lack of BK channel function is partially ameliorated by upregulation of presynaptic Shaker (Sh) IA current to limit excessive transmitter release in addition to postsynaptic glutamate receptor recomposition that reduces the quantal size.
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Affiliation(s)
- Atsushi Ueda
- Department of Biology, University of Iowa Iowa City, IA, USA
| | - Chun-Fang Wu
- Department of Biology, University of Iowa Iowa City, IA, USA
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Blunk AD, Akbergenova Y, Cho RW, Lee J, Walldorf U, Xu K, Zhong G, Zhuang X, Littleton JT. Postsynaptic actin regulates active zone spacing and glutamate receptor apposition at the Drosophila neuromuscular junction. Mol Cell Neurosci 2014; 61:241-54. [PMID: 25066865 PMCID: PMC4134997 DOI: 10.1016/j.mcn.2014.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/14/2014] [Accepted: 07/23/2014] [Indexed: 12/26/2022] Open
Abstract
Synaptic communication requires precise alignment of presynaptic active zones with postsynaptic receptors to enable rapid and efficient neurotransmitter release. How transsynaptic signaling between connected partners organizes this synaptic apparatus is poorly understood. To further define the mechanisms that mediate synapse assembly, we carried out a chemical mutagenesis screen in Drosophila to identify mutants defective in the alignment of active zones with postsynaptic glutamate receptor fields at the larval neuromuscular junction. From this screen we identified a mutation in Actin 57B that disrupted synaptic morphology and presynaptic active zone organization. Actin 57B, one of six actin genes in Drosophila, is expressed within the postsynaptic bodywall musculature. The isolated allele, act(E84K), harbors a point mutation in a highly conserved glutamate residue in subdomain 1 that binds members of the Calponin Homology protein family, including spectrin. Homozygous act(E84K) mutants show impaired alignment and spacing of presynaptic active zones, as well as defects in apposition of active zones to postsynaptic glutamate receptor fields. act(E84K) mutants have disrupted postsynaptic actin networks surrounding presynaptic boutons, with the formation of aberrant actin swirls previously observed following disruption of postsynaptic spectrin. Consistent with a disruption of the postsynaptic actin cytoskeleton, spectrin, adducin and the PSD-95 homolog Discs-Large are all mislocalized in act(E84K) mutants. Genetic interactions between act(E84K) and neurexin mutants suggest that the postsynaptic actin cytoskeleton may function together with the Neurexin-Neuroligin transsynaptic signaling complex to mediate normal synapse development and presynaptic active zone organization.
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Affiliation(s)
- Aline D Blunk
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Yulia Akbergenova
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Richard W Cho
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Jihye Lee
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; The Department of Oral Pathology, School of Dentistry, Pusan National University, Republic of Korea
| | - Uwe Walldorf
- Department of Developmental Biology, University of Saarland, Homburg, Saar, Germany
| | - Ke Xu
- Howard Hughes Medical Institute (HHMI), Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Guisheng Zhong
- Howard Hughes Medical Institute (HHMI), Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Xiaowei Zhuang
- Howard Hughes Medical Institute (HHMI), Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States; Department of Physics, Harvard University, Cambridge, MA 02138, United States
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
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de Castro C, Titlow J, Majeed ZR, Cooper RL. Analysis of various physiological salines for heart rate, CNS function, and synaptic transmission at neuromuscular junctions in Drosophila melanogaster larvae. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 200:83-92. [PMID: 24190421 DOI: 10.1007/s00359-013-0864-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/12/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
Abstract
Drosophila serves as a playground for examining the effects of genetic mutations on development, physiological function and behavior. Many physiological measures that address the effects of mutations require semi-intact or cultured preparations. To obtain consistent physiological recordings, cellular function needs to remain viable. Numerous physiological salines have been developed for fly preparations, with emphasis on nervous system viability. The commonly used saline drifts in pH and will cause an alteration in the heart rate. We identify a saline that maintains a stable pH and physiological function in the larval heart, skeletal neuromuscular junction, and ventral nerve cord preparations. Using these common assays, we screened various pH buffers of differing concentrations to identify optimum conditions. Buffers at 25 mM produce a stable heart rate with minimal variation in pH. Excitatory junction potentials evoked directly on larval muscles or through sensory-CNS-motor circuits were unaffected by at buffers at 25 mM. The salines examined did not impede the modulatory effect of serotonin on heart rate or neural activity. Together, our results indicate that the higher buffer concentrations needed to stabilize pH in HL3 hemolymph-like saline do not interfere with the acute function of neurons or cardiac myocytes.
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Affiliation(s)
- Clara de Castro
- Sayre School, Upper School, 194 North Limestone, Lexington, KY, 40507, USA
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Lee J, Ueda A, Wu CF. Distinct roles of Drosophila cacophony and Dmca1D Ca(2+) channels in synaptic homeostasis: genetic interactions with slowpoke Ca(2+) -activated BK channels in presynaptic excitability and postsynaptic response. Dev Neurobiol 2013; 74:1-15. [PMID: 23959639 DOI: 10.1002/dneu.22120] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 07/24/2013] [Accepted: 08/13/2013] [Indexed: 01/06/2023]
Abstract
Ca(2+) influx through voltage-activated Ca(2+) channels and its feedback regulation by Ca(2+) -activated K(+) (BK) channels is critical in Ca(2+) -dependent cellular processes, including synaptic transmission, growth and homeostasis. Here we report differential roles of cacophony (CaV 2) and Dmca1D (CaV 1) Ca(2+) channels in synaptic transmission and in synaptic homeostatic regulations induced by slowpoke (slo) BK channel mutations. At Drosophila larval neuromuscular junctions (NMJs), a well-established homeostatic mechanism of transmitter release enhancement is triggered by experimentally suppressing postsynaptic receptor response. In contrast, a distinct homeostatic adjustment is induced by slo mutations. To compensate for the loss of BK channel control presynaptic Sh K(+) current is upregulated to suppress transmitter release, coupled with a reduction in quantal size. We demonstrate contrasting effects of cac and Dmca1D channels in decreasing transmitter release and muscle excitability, respectively, consistent with their predominant pre- vs. postsynaptic localization. Antibody staining indicated reduced postsynaptic GluRII receptor subunit density and altered ratio of GluRII A and B subunits in slo NMJs, leading to quantal size reduction. Such slo-triggered modifications were suppressed in cac;;slo larvae, correlated with a quantal size reversion to normal in double mutants, indicating a role of cac Ca(2+) channels in slo-triggered homeostatic processes. In Dmca1D;slo double mutants, the quantal size and quantal content were not drastically different from those of slo, although Dmca1D suppressed the slo-induced satellite bouton overgrowth. Taken together, cac and Dmca1D Ca(2+) channels differentially contribute to functional and structural aspects of slo-induced synaptic modifications.
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Affiliation(s)
- Jihye Lee
- Interdisciplinary Program in Neuroscience, The University of Iowa, Iowa City, IA 52242, USA.,Department of Oral Pathology, School of Dentistry, Pusan National University, Yangsan-Si, Kyoungsangnam-Do, 626-870, Korea
| | - Atsushi Ueda
- Department of Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Chun-Fang Wu
- Interdisciplinary Program in Neuroscience, The University of Iowa, Iowa City, IA 52242, USA.,Department of Biology, The University of Iowa, Iowa City, IA 52242, USA
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Neuron-type specific functions of DNT1, DNT2 and Spz at the Drosophila neuromuscular junction. PLoS One 2013; 8:e75902. [PMID: 24124519 PMCID: PMC3790821 DOI: 10.1371/journal.pone.0075902] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 08/17/2013] [Indexed: 02/08/2023] Open
Abstract
Retrograde growth factors regulating synaptic plasticity at the neuromuscular junction (NMJ) in Drosophila have long been predicted but their discovery has been scarce. In vertebrates, such retrograde factors produced by the muscle include GDNF and the neurotrophins (NT: NGF, BDNF, NT3 and NT4). NT superfamily members have been identified throughout the invertebrates, but so far no functional in vivo analysis has been carried out at the NMJ in invertebrates. The NT family of proteins in Drosophila is formed of DNT1, DNT2 and Spätzle (Spz), with sequence, structural and functional conservation relative to mammalian NTs. Here, we investigate the functions of Drosophila NTs (DNTs) at the larval NMJ. All three DNTs are expressed in larval body wall muscles, targets for motor-neurons. Over-expression of DNTs in neurons, or the activated form of the Spz receptor, Toll10b, in neurons only, rescued the semi-lethality of spz2 and DNT141, DNT2e03444 double mutants, indicating retrograde functions in neurons. In spz2 mutants, DNT141, DNT2e03444 double mutants, and upon over-expression of the DNTs, NMJ size and bouton number increased. Boutons were morphologically abnormal. Mutations in spz and DNT1,DNT2 resulted in decreased number of active zones per bouton and decreased active zone density per terminal. Alterations in DNT function induced ghost boutons and synaptic debris. Evoked junction potentials were normal in spz2 mutants and DNT141, DNT2e03444 double mutants, but frequency and amplitude of spontaneous events were reduced in spz2 mutants suggesting defective neurotransmission. Our data indicate that DNTs are produced in muscle and are required in neurons for synaptogenesis. Most likely alterations in DNT function and synapse formation induce NMJ plasticity leading to homeostatic adjustments that increase terminal size restoring overall synaptic transmission. Data suggest that Spz functions with neuron-type specificity at the muscle 4 NMJ, and DNT1 and DNT2 function together at the muscles 6,7 NMJ.
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Caplan SL, Milton SL, Dawson-Scully K. A cGMP-dependent protein kinase (PKG) controls synaptic transmission tolerance to acute oxidative stress at the Drosophila larval neuromuscular junction. J Neurophysiol 2013; 109:649-58. [DOI: 10.1152/jn.00784.2011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increasing evidence demonstrates that modulating the cGMP-dependent protein kinase G (PKG) pathway produces an array of behavioral phenotypes in the fruit fly, Drosophila melanogaster. Altering PKG activity, either genetically via the foraging ( for) gene or using pharmacology modifies tolerance to acute abiotic stresses such as hyperthermia and hypoxia. PKG signaling has been shown to modulate neuroprotection in many experimental paradigms of acute brain trauma and chronic neurodegenerative diseases. However, relatively little is known about how this stress-induced neuroprotective mechanism affects neural communication. In this study, we investigated the role PKG activity has on synaptic transmission at the Drosophila larval neuromuscular junction (NMJ) during acute oxidative stress and found that the application of 2.25 mM hydrogen peroxide (H2O2) disrupts synaptic function by rapidly increasing the rate of neuronal failure. Here, we report that reducing PKG activity through either natural genetic variation or an induced mutation of the for gene increases synaptic tolerance during acute oxidative conditions. Furthermore, pharmacological manipulations revealed that neurotransmission is significantly extended during acute H2O2 exposure upon inhibition of the PKG pathway. Conversely, activation of this signaling cascade using either genetics or pharmacology significantly reduced the time until synaptic failure. Therefore, these findings suggest a potential role for PKG activity to regulate the tolerance of synaptic transmission during acute oxidative stress, where inhibition promotes functional protection while activation increases susceptibility to neurotransmission breakdown.
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Affiliation(s)
- Stacee Lee Caplan
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
| | - Sarah L. Milton
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
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Glutamate receptors in synaptic assembly and plasticity: case studies on fly NMJs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 970:3-28. [PMID: 22351049 DOI: 10.1007/978-3-7091-0932-8_1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The molecular and cellular mechanisms that control the composition and functionality of ionotropic glutamate receptors may be considered as most important "set screws" for adjusting excitatory transmission in the course of developmental and experience-dependent changes within neural networks. The Drosophila larval neuromuscular junction has emerged as one important invertebrate model system to study the formation, maintenance, and plasticity-related remodeling of glutamatergic synapses in vivo. By exploiting the unique genetic accessibility of this organism combined with diverse tools for manipulation and analysis including electrophysiology and state of the art imaging, considerable progress has been made to characterize the role of glutamate receptors during the orchestration of junctional development, synaptic activity, and synaptogenesis. Following an introduction to basic features of this model system, we will mainly focus on conceptually important findings such as the selective impact of glutamate receptor subtypes on the formation of new synapses, the coordination of presynaptic maturation and receptor subtype composition, the role of nonvesicularly released glutamate on the synaptic localization of receptors, or the homeostatic feedback of receptor functionality on presynaptic transmitter release.
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30
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Meinertzhagen IA, Lee CH. The genetic analysis of functional connectomics in Drosophila. ADVANCES IN GENETICS 2012; 80:99-151. [PMID: 23084874 DOI: 10.1016/b978-0-12-404742-6.00003-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Fly and vertebrate nervous systems share many organizational features, such as layers, columns and glomeruli, and utilize similar synaptic components, such as ion channels and receptors. Both also exhibit similar network features. Recent technological advances, especially in electron microscopy, now allow us to determine synaptic circuits and identify pathways cell-by-cell, as part of the fly's connectome. Genetic tools provide the means to identify synaptic components, as well as to record and manipulate neuronal activity, adding function to the connectome. This review discusses technical advances in these emerging areas of functional connectomics, offering prognoses in each and identifying the challenges in bridging structural connectomics to molecular biology and synaptic physiology, thereby determining fundamental mechanisms of neural computation that underlie behavior.
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Affiliation(s)
- Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.
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31
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Chen Y, Yang M, Deng J, Chen X, Ye Y, Zhu L, Liu J, Ye H, Shen Y, Li Y, Rao EJ, Fushimi K, Zhou X, Bigio EH, Mesulam M, Xu Q, Wu JY. Expression of human FUS protein in Drosophila leads to progressive neurodegeneration. Protein Cell 2011; 2:477-86. [PMID: 21748598 DOI: 10.1007/s13238-011-1065-7] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 06/23/2011] [Indexed: 12/12/2022] Open
Abstract
Mutations in the Fused in sarcoma/Translated in liposarcoma gene (FUS/TLS, FUS) have been identified among patients with amyotrophic lateral sclerosis (ALS). FUS protein aggregation is a major pathological hallmark of FUS proteinopathy, a group of neurodegenerative diseases characterized by FUS-immunoreactive inclusion bodies. We prepared transgenic Drosophila expressing either the wild type (Wt) or ALS-mutant human FUS protein (hFUS) using the UAS-Gal4 system. When expressing Wt, R524S or P525L mutant FUS in photoreceptors, mushroom bodies (MBs) or motor neurons (MNs), transgenic flies show age-dependent progressive neural damages, including axonal loss in MB neurons, morphological changes and functional impairment in MNs. The transgenic flies expressing the hFUS gene recapitulate key features of FUS proteinopathy, representing the first stable animal model for this group of devastating diseases.
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Affiliation(s)
- Yanbo Chen
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Science and Peking Union Medical College, Tsinghua University, Beijing, China
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32
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Abstract
The synaptic active zone, the site where Ca(2+)-triggered fusion of synaptic vesicles takes place, is commonly associated with protein-rich, electron-dense cytomatrices. The molecular composition and functional role of active zones, especially in the context of vesicular exo- and endocytosis, are under intense investigation. Per se, Drosophila synapses, which display so-called T-bars as electron-dense specializations, should be a highly suitable model system, as they allow for a combination of efficient genetics with ultrastructural and electrophysiological analyses. However, it needed a biochemical approach of the Buchner laboratory to "molecularly" access the T-bar by identification of the CAST/ERC-family member Bruchpilot as the first T-bar-residing protein. Genetic elimination of Bruchpilot revealed that the protein is essential for T-bar formation, calcium channel clustering, and hence proper vesicle fusion and patterned synaptic plasticity. Recently, Bruchpilot was shown to directly shape the T-bar, likely by adopting an elongated conformation. Moreover, first mechanisms that control the availability of Bruchpilot for T-bar assembly were described. This review seeks to summarize the information on T-bar structure, as well as on functional aspects, formulating the hypothesis that T-bars are genuine "plasticity modules."
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Affiliation(s)
- Carolin Wichmann
- NeuroCure Cluster of Excellence, Charité Berlin, Berlin, Germany
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33
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Godena VK, Romano G, Romano M, Appocher C, Klima R, Buratti E, Baralle FE, Feiguin F. TDP-43 regulates Drosophila neuromuscular junctions growth by modulating Futsch/MAP1B levels and synaptic microtubules organization. PLoS One 2011; 6:e17808. [PMID: 21412434 PMCID: PMC3055892 DOI: 10.1371/journal.pone.0017808] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 02/11/2011] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is an evolutionarily conserved RNA binding protein recently associated with the pathogenesis of different neurological diseases. At the moment, neither its physiological role in vivo nor the mechanisms that may lead to neurodegeneration are well known. Previously, we have shown that TDP-43 mutant flies presented locomotive alterations and structural defects at the neuromuscular junctions. We have now investigated the functional mechanism leading to these phenotypes by screening several factors known to be important for synaptic growth or bouton formation. As a result we found that alterations in the organization of synaptic microtubules correlate with reduced protein levels in the microtubule associated protein futsch/MAP1B. Moreover, we observed that TDP-43 physically interacts with futsch mRNA and that its RNA binding capacity is required to prevent futsch down regulation and synaptic defects.
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Affiliation(s)
- Vinay K. Godena
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Giulia Romano
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Maurizio Romano
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Chiara Appocher
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Raffaella Klima
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Emanuele Buratti
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Francisco E. Baralle
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
- * E-mail: (FEB); (FF)
| | - Fabian Feiguin
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
- * E-mail: (FEB); (FF)
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34
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Thomas U, Kobler O, Gundelfinger ED. TheDrosophilaLarval Neuromuscular Junction as a Model for Scaffold Complexes at Glutamatergic Synapses: Benefits and Limitations. J Neurogenet 2010; 24:109-19. [DOI: 10.3109/01677063.2010.493589] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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35
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Desai-Shah M, Cooper RL. Different mechanisms of Ca2+ regulation that influence synaptic transmission: comparison between crayfish and Drosophila neuromuscular junctions. Synapse 2010; 63:1100-21. [PMID: 19650116 DOI: 10.1002/syn.20695] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A brief historical background on synaptic transmission in relation to Ca(2+) dynamics and short-term facilitation is described. This study focuses on the mechanisms responsible for the regulation of intracellular calcium concentration ([Ca(2+)](i)) in high output terminals of larval Drosophila compared to a low-output terminal of the crayfish neuromuscular junction (NMJ). Three processes; plasmalemmal Na(+)/Ca(2+) exchanger [NCX], Ca(2+)-ATPase (PMCA), and sarcoplasmic/endoplasmic Ca(2+)-ATPase (SERCA) are important in regulating the [Ca(2+)](i) are examined. When the NCX is compromised by reduced [Na(+)](o), no consistent effect occurred; but a NCX blocker KB-R7943 decreased the excitatory postsynaptic potential (EPSP) amplitudes. Compromising the PMCA with pH 8.8 resulted in an increase in EPSP amplitude but treatment with a PMCA specific inhibitor carboxyeosin produced opposite results. Thapsigargin exposure to block the SERCA generally decreases EPSP amplitude. Compromising the activity of the above Ca(2+) regulating proteins had no substantial effects on short-term depression. The Kum(170TS) strain (with dysfunctional SERCA), showed a decrease in EPSP amplitudes including the first EPSP within the train. Synaptic transmission is altered by reducing the function of the above three [Ca(2+)](i) regulators; but they are not consistent among different species as expected. Results in crayfish NMJ were more consistent with expected results as compared to the Drosophila NMJ. It is predicated that different mechanisms are used for regulating the [Ca(2+)](i) in high and low output synaptic terminals.
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Affiliation(s)
- Mohati Desai-Shah
- Department of Biology, University of Kentucky, Lexington, Kentucky 40506-0225, USA
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36
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Lee JY, Bhatt D, Bhatt D, Chung WY, Cooper RL. Furthering pharmacological and physiological assessment of the glutamatergic receptors at the Drosophila neuromuscular junction. Comp Biochem Physiol C Toxicol Pharmacol 2009; 150:546-57. [PMID: 19695344 DOI: 10.1016/j.cbpc.2009.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 08/03/2009] [Accepted: 08/06/2009] [Indexed: 11/23/2022]
Abstract
Drosophila melanogaster larval neuromuscular junctions (NMJs) serve as a model for synaptic physiology. The molecular sequences of the postsynaptic glutamate receptors have been described; however, the pharmacological profile has not been fully elucidated. The postsynaptic molecular sequence suggests a novel glutamate receptor subtype. Kainate does not depolarize the muscle, but dampens evoked EPSP amplitudes. Quantal responses show a decreased amplitude and area under the voltage curve indicative of reduced postsynaptic receptor sensitivity to glutamate transmission. ATPA, a kainate receptor agonist, did not mimic kainate's action. The metabotropic glutamate receptor agonist t-ACPD had no effect. Domoic acid, a kainate/AMPA receptor agonist, blocks the postsynaptic receptors without depolarizing the muscle. However, SYM 2081, a kainate receptor agonist, did depolarize the muscle and reduce the EPSP amplitude at 1 mM but not at 0.1 mM. This supports the notion that these are generally a quisqualate subtype receptors with some oddities in the pharmacological profile. The results suggest a direct postsynaptic action of kainate due to partial antagonist action on the quisqualate receptors. There does not appear to be presynaptic auto-regulation via a kainate receptor subtype or a metabotropic auto-receptor. This study aids in furthering the pharmokinetic profiling and specificity of the receptor subtypes.
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Affiliation(s)
- J-Y Lee
- Department of Biology, University of Kentucky, Lexington, KY, USA 40506-0225, USA
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37
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Dason JS, Romero-Pozuelo J, Marin L, Iyengar BG, Klose MK, Ferrús A, Atwood HL. Frequenin/NCS-1 and the Ca2+-channel alpha1-subunit co-regulate synaptic transmission and nerve-terminal growth. J Cell Sci 2009; 122:4109-21. [PMID: 19861494 DOI: 10.1242/jcs.055095] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Drosophila Frequenin (Frq) and its mammalian and worm homologue, NCS-1, are Ca(2+)-binding proteins involved in neurotransmission. Using site-specific recombination in Drosophila, we created two deletions that removed the entire frq1 gene and part of the frq2 gene, resulting in no detectable Frq protein. Frq-null mutants were viable, but had defects in larval locomotion, deficient synaptic transmission, impaired Ca(2+) entry and enhanced nerve-terminal growth. The impaired Ca(2+) entry was sufficient to account for reduced neurotransmitter release. We hypothesized that Frq either modulates Ca(2+) channels, or that it regulates the PI4Kbeta pathway as described in other organisms. To determine whether Frq interacts with PI4Kbeta with consequent effects on Ca(2+) channels, we first characterized a PI4Kbeta-null mutant and found that PI4Kbeta was dispensable for synaptic transmission and nerve-terminal growth. Frq gain-of-function phenotypes remained present in a PI4Kbeta-null background. We conclude that the effects of Frq are not due to an interaction with PI4Kbeta. Using flies that were trans-heterozygous for a null frq allele and a null cacophony (encoding the alpha(1)-subunit of voltage-gated Ca(2+) channels) allele, we show a synergistic effect between these proteins in neurotransmitter release. Gain-of-function Frq phenotypes were rescued by a hypomorphic cacophony mutation. Overall, Frq modulates Ca(2+) entry through a functional interaction with the alpha(1) voltage-gated Ca(2+)-channel subunit; this interaction regulates neurotransmission and nerve-terminal growth.
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Affiliation(s)
- Jeffrey S Dason
- Department of Physiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
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38
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Branco T, Staras K. The probability of neurotransmitter release: variability and feedback control at single synapses. Nat Rev Neurosci 2009; 10:373-83. [PMID: 19377502 DOI: 10.1038/nrn2634] [Citation(s) in RCA: 243] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Information transfer at chemical synapses occurs when vesicles fuse with the plasma membrane and release neurotransmitter. This process is stochastic and its likelihood of occurrence is a crucial factor in the regulation of signal propagation in neuronal networks. The reliability of neurotransmitter release can be highly variable: experimental data from electrophysiological, molecular and imaging studies have demonstrated that synaptic terminals can individually set their neurotransmitter release probability dynamically through local feedback regulation. This local tuning of transmission has important implications for current models of single-neuron computation.
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Affiliation(s)
- Tiago Branco
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, WC1E 6BT, UK.
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39
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Rushton E, Rohrbough J, Broadie K. Presynaptic secretion of mind-the-gap organizes the synaptic extracellular matrix-integrin interface and postsynaptic environments. Dev Dyn 2009; 238:554-71. [PMID: 19235718 PMCID: PMC2677818 DOI: 10.1002/dvdy.21864] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Mind-the-Gap (MTG) is required during synaptogenesis of the Drosophila glutamatergic neuromuscular junction (NMJ) to organize the postsynaptic domain. Here, we generate MTG::GFP transgenic animals to demonstrate MTG is synaptically targeted, secreted, and localized to punctate domains in the synaptic extracellular matrix (ECM). Drosophila NMJs form specialized ECM carbohydrate domains, with carbohydrate moieties and integrin ECM receptors occupying overlapping territories. Presynaptically secreted MTG recruits and reorganizes secreted carbohydrates, and acts to recruit synaptic integrins and ECM glycans. Transgenic MTG::GFP expression rescues hatching, movement, and synaptogenic defects in embryonic-lethal mtg null mutants. Targeted neuronal MTG expression rescues mutant synaptogenesis defects, and increases rescue of adult viability, supporting an essential neuronal function. These results indicate that presynaptically secreted MTG regulates the ECM-integrin interface, and drives an inductive mechanism for the functional differentiation of the postsynaptic domain of glutamatergic synapses. We suggest that MTG pioneers a novel protein family involved in ECM-dependent synaptic differentiation.
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Affiliation(s)
| | | | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt Brain Institute, Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee
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40
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Sjöström PJ, Rancz EA, Roth A, Häusser M. Dendritic excitability and synaptic plasticity. Physiol Rev 2008; 88:769-840. [PMID: 18391179 DOI: 10.1152/physrev.00016.2007] [Citation(s) in RCA: 418] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Most synaptic inputs are made onto the dendritic tree. Recent work has shown that dendrites play an active role in transforming synaptic input into neuronal output and in defining the relationships between active synapses. In this review, we discuss how these dendritic properties influence the rules governing the induction of synaptic plasticity. We argue that the location of synapses in the dendritic tree, and the type of dendritic excitability associated with each synapse, play decisive roles in determining the plastic properties of that synapse. Furthermore, since the electrical properties of the dendritic tree are not static, but can be altered by neuromodulators and by synaptic activity itself, we discuss how learning rules may be dynamically shaped by tuning dendritic function. We conclude by describing how this reciprocal relationship between plasticity of dendritic excitability and synaptic plasticity has changed our view of information processing and memory storage in neuronal networks.
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Affiliation(s)
- P Jesper Sjöström
- Wolfson Institute for Biomedical Research and Department of Physiology, University College London, London, United Kingdom
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41
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Lee J, Ueda A, Wu CF. Pre- and post-synaptic mechanisms of synaptic strength homeostasis revealed by slowpoke and shaker K+ channel mutations in Drosophila. Neuroscience 2008; 154:1283-96. [PMID: 18539401 DOI: 10.1016/j.neuroscience.2008.04.043] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/11/2008] [Accepted: 04/15/2008] [Indexed: 11/24/2022]
Abstract
We report naturally occurring, systematic variations in synaptic strength at neuromuscular junctions along the dorsal-ventral (D-V) axis of the Drosophila larval body wall. These gradual changes were correlated with differences in presynaptic neurotransmitter release regulated by nerve terminal excitability and in postsynaptic receptor composition influencing miniature excitatory junctional potential (mEJP) amplitude. Surprisingly, synaptic strength and D-V differentials at physiological Ca(2+) levels were not significantly altered in slowpoke (slo) and Shaker (Sh) mutants, despite their defects in two major repolarizing forces, Ca(2+)-activated Slo (BK) and voltage-activated Sh currents, respectively. However, lowering [Ca(2+)](o) levels revealed greatly altered synaptic mechanisms in these mutants, indicated by drastically enhanced excitatory junctional potentials (EJPs) in Sh but paradoxically reduced EJPs in slo. Removal of Sh current in slo mutants by 4-aminopyridine blockade or by combining slo with Sh mutations led to strikingly increased synaptic transmission, suggesting upregulation of presynaptic Sh current to limit excessive neurotransmitter release in the absence of Slo current. In addition, slo mutants displayed altered immunoreactivity intensity ratio between DGluRIIA and DGluRIIB receptor subunits. This modified receptor composition caused smaller mEJP amplitudes, further preventing excessive transmission in the absence of Slo current. Such compensatory regulations were prevented by rutabaga (rut) adenylyl cyclase mutations in rut slo double mutants, demonstrating a novel role of rut in homeostatic plasticity, in addition to its well-established function in learning behavior.
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Affiliation(s)
- J Lee
- Interdisciplinary Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
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42
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Mileva-Seitz V, Xiao C, Seroude L, Robertson RM. Tissue-specific targeting of Hsp26 has no effect on heat resistance of neural function in larval Drosophila. Cell Stress Chaperones 2008; 13:85-95. [PMID: 18347945 PMCID: PMC2666220 DOI: 10.1007/s12192-008-0016-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 09/10/2007] [Accepted: 09/11/2007] [Indexed: 11/29/2022] Open
Abstract
Hsp26 belongs to the small heat-shock protein family and is normally expressed in all cells during heat stress. We aimed to determine if overexpression of this protein protects behavior and neural function in Drosophila melanogaster during heat stress, as has previously been shown for Hsp70. We used the UAS-GAL4 expression system to drive expression of Hsp26 in the whole animal (ubiquitously), in the motoneurons, and in the muscles of wandering third-instar larvae. There were slight increases in time to crawling failure and normalized excitatory junction potential (EJP) area for some of the transgenic lines, but these were not consistent. In addition, Hsp26 had no effect on the temperature at failure of EJPs, normalized EJP peak amplitude, and normalized EJP half-width. Overexpression larvae had a similar number of motoneuronal boutons and length of nerve terminals as controls, indicating that the occasional protective effects on locomotion were not due to changes at the synapse. We conclude that overexpression had a small thermoprotective effect on locomotion and no effect on neural function. As it has been shown that Hsp26 requires action of other Hsps to reactivate the denatured proteins to which it binds, we propose that at least in larvae, the function of Hsp26 was masked in the relative absence of other Hsps.
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Affiliation(s)
- Viara Mileva-Seitz
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6 Canada
- Institute of Medical Science, University of Toronto, 7213 Medical Sciences Building, 1 King’s College Circle, Toronto, ON M5S 1A8 Canada
| | - Chengfeng Xiao
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6 Canada
| | - Laurent Seroude
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6 Canada
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43
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Li J, Ashley J, Budnik V, Bhat MA. Crucial role of Drosophila neurexin in proper active zone apposition to postsynaptic densities, synaptic growth, and synaptic transmission. Neuron 2007; 55:741-55. [PMID: 17785181 PMCID: PMC2039911 DOI: 10.1016/j.neuron.2007.08.002] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 07/17/2007] [Accepted: 08/07/2007] [Indexed: 10/22/2022]
Abstract
Neurexins have been proposed to function as major mediators of the coordinated pre- and postsynaptic apposition. However, key evidence for this role in vivo has been lacking, particularly due to gene redundancy. Here, we have obtained null mutations in the single Drosophila neurexin gene (dnrx). dnrx loss of function prevents the normal proliferation of synaptic boutons at glutamatergic neuromuscular junctions, while dnrx gain of function in neurons has the opposite effect. DNRX mostly localizes to the active zone of presynaptic terminals. Conspicuously, dnrx null mutants display striking defects in synaptic ultrastructure, with the presence of detachments between pre- and postsynaptic membranes, abnormally long active zones, and increased number of T bars. These abnormalities result in corresponding alterations in synaptic transmission with reduced quantal content. Together, our results provide compelling evidence for an in vivo role of neurexins in the modulation of synaptic architecture and adhesive interactions between pre- and postsynaptic compartments.
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Affiliation(s)
- Jingjun Li
- Curriculum in Neurobiology, Department of Cell and Molecular Physiology, UNC-Neuroscience Center, Neurodevelopmental Disorders Research Center, University of North Carolina School of Medicine Chapel Hill, NC 27599-7545
| | - James Ashley
- Department of Neurobiology University of Massachusetts Medical School Worcester, MA 01605
| | - Vivian Budnik
- Department of Neurobiology University of Massachusetts Medical School Worcester, MA 01605
| | - Manzoor A. Bhat
- Curriculum in Neurobiology, Department of Cell and Molecular Physiology, UNC-Neuroscience Center, Neurodevelopmental Disorders Research Center, University of North Carolina School of Medicine Chapel Hill, NC 27599-7545
- *To whom correspondence should be addressed: Manzoor Bhat, Ph.D., Neuroscience Research Building, Room #5109, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7545, Tel: (919) 966-1018, Fax: (919) 843-2777,
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Romero-Pozuelo J, Dason JS, Atwood HL, Ferrús A. Chronic and acute alterations in the functional levels of Frequenins 1 and 2 reveal their roles in synaptic transmission and axon terminal morphology. Eur J Neurosci 2007; 26:2428-43. [DOI: 10.1111/j.1460-9568.2007.05877.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Besse F, Mertel S, Kittel RJ, Wichmann C, Rasse TM, Sigrist SJ, Ephrussi A. The Ig cell adhesion molecule Basigin controls compartmentalization and vesicle release at Drosophila melanogaster synapses. ACTA ACUST UNITED AC 2007; 177:843-55. [PMID: 17548512 PMCID: PMC2064284 DOI: 10.1083/jcb.200701111] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Synapses can undergo rapid changes in size as well as in their vesicle release function during both plasticity processes and development. This fundamental property of neuronal cells requires the coordinated rearrangement of synaptic membranes and their associated cytoskeleton, yet remarkably little is known of how this coupling is achieved. In a GFP exon-trap screen, we identified Drosophila melanogaster Basigin (Bsg) as an immunoglobulin domain-containing transmembrane protein accumulating at periactive zones of neuromuscular junctions. Bsg is required pre- and postsynaptically to restrict synaptic bouton size, its juxtamembrane cytoplasmic residues being important for that function. Bsg controls different aspects of synaptic structure, including distribution of synaptic vesicles and organization of the presynaptic cortical actin cytoskeleton. Strikingly, bsg function is also required specifically within the presynaptic terminal to inhibit nonsynchronized evoked vesicle release. We thus propose that Bsg is part of a transsynaptic complex regulating synaptic compartmentalization and strength, and coordinating plasma membrane and cortical organization.
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Affiliation(s)
- Florence Besse
- Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany
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46
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Hamilton J, Dillaman RM, Worden MK. Neuromuscular synapses on the dactyl opener muscle of the lobster Homarus americanus. Cell Tissue Res 2006; 326:823-34. [PMID: 16788836 DOI: 10.1007/s00441-006-0221-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Accepted: 04/11/2006] [Indexed: 11/24/2022]
Abstract
The crustacean dactyl opener neuromuscular system has been studied extensively as a model system that exhibits several forms of synaptic plasticity. We report the ultrastructural features of the synapses on dactyl opener of the lobster (Homarus americanus) as determined by examination of serial thin sections. Several innervation sites supplied by an inhibitory motoneuron have been observed without nearby excitatory innervation, indicating that excitatory and inhibitory inputs to the muscle are not always closely matched. The ultrastructural features of the lobster synapses are generally similar to those described previously for the homologous crayfish muscle, with one major distinction: few dense bars are seen at the presynaptic membranes of these lobster synapses. The majority of the lobster neuromuscular synapses lack dense bars altogether, and the mean number of dense bars per synapse is relatively low. In view of the finding that the physiology of the lobster dactyl opener synapses is similar to that reported for crayfish, these ultrastructural observations suggest that the structural complexity of the synapses may not be a critical factor determining synaptic plasticity.
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Affiliation(s)
- Jonna Hamilton
- Department of Neuroscience, University of Virginia, P.O. Box 801392, Charlottesville, VA 22908, USA
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Lnenicka GA, Theriault K, Monroe R. Sexual differentiation of identified motor terminals inDrosophila larvae. ACTA ACUST UNITED AC 2006; 66:488-98. [PMID: 16470738 DOI: 10.1002/neu.20234] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In Drosophila, we have found that some of the motor terminals in wandering third-instar larvae are sexually differentiated. In three out of the four body-wall muscle fibers that we examined, we found female terminals that produced a larger synaptic response than their male counterparts. The single motor terminal that innervates muscle fiber 5 produces an EPSP that is 69% larger in females than in males. This is due to greater release of transmitter from female than male synaptic terminals because the amplitude of spontaneous miniature EPSPs was similar in male and female muscle fibers. This sexual difference exists throughout the third-instar: it is seen in both early (foraging) and late (wandering) third-instar larvae. The sexual differentiation appears to be neuron specific and not muscle specific because the same axon produces Is terminals on muscle fibers 2 and 4, and both terminals produce larger EPSCs in females than males. Whereas, the Ib terminals innervating muscle fibers 2 and 4 are not sexually differentiated. The differences in transmitter release are not due to differences in the size of the motor terminals. For the terminal on muscle fiber 5 and the Is terminal on muscle fiber 4, there were no differences in terminal length, the number of branches, or the number of synaptic boutons in males compared to females. These sexual differences in neuromuscular synaptic physiology may be related to male-female differences in locomotion.
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Affiliation(s)
- Gregory A Lnenicka
- Department of Biological Sciences, University at Albany, SUNY, Albany, New York 12222, USA.
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Prokop A. Organization of the Efferent System and Structure of Neuromuscular Junctions In Drosophila. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2006; 75:71-90. [PMID: 17137924 DOI: 10.1016/s0074-7742(06)75004-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Andreas Prokop
- Faculty of Life Sciences, The University of Manchester, Manchester M13 9PT, United Kingdom
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Griffith LC, Budnik V. Plasticity and second messengers during synapse development. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2006; 75:237-65. [PMID: 17137931 PMCID: PMC4664443 DOI: 10.1016/s0074-7742(06)75011-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Effective function of the locomotor system in the Drosophila larva requires a continuous adjustment of synaptic architecture and neurotransmission at the neuromuscular junction (NMJ). This feature has made the larval NMJ a favorite model to study the genetic and molecular mechanisms underlying synapse plasticity. This chapter will review experimental strategies used to study plasticity at the NMJ, the cellular parameters affected during plastic changes, and many of the known molecules involved in plastic changes. In addition, signal transduction pathways activated during plasticity will be discussed.
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Affiliation(s)
- Leslie C. Griffith
- Dept of Biology and National Center for Behavioral Genomics, Brandeis University, 415 South St., Waltham, MA, 02454, USA
- Corresponding Author: phone: 781 736 3125, FAX: 781 736 3107,
| | - Vivian Budnik
- Department of Neurobiology, University of Massachusetts Medical School, Aaron Lazare Medical Research Building, 364 Plantation Street Worcester, MA 01605-2324, USA
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50
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Ataman B, Budnik V, Thomas U. Scaffolding proteins at the Drosophila neuromuscular junction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2006; 75:181-216. [PMID: 17137929 DOI: 10.1016/s0074-7742(06)75009-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Bulent Ataman
- Department of Neurobiology, University of Massachusetts, Medical School, Worcester, Massachusetts 01605, USA
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